Coolant flows from the bottom of the radiator (drawn by WP) into the block through the cylinder cores (skirt jackets) to the cyl heads and connected in the intake manifold @ the thermostat housing. It is then regulated flow into the radiator.

Take readings all along this path(s) to determine if any hot spots/blockages.

CORRECTION (To Be More Concise)-

The coolant flows from the WP to and around the cylinder barrels and then is directed to the rear of the cylinder heads where it then flows toward the front of the engine. The coolant head flow is then combined at the front coolant channel in the intake manifold and then is subject to thermostat control.